Detergent composition

ABSTRACT

Primary and secondary alkylsulfonates with carbon numbers lower than those which afford optimum detergency are used as hydrotropes in detergent formulations. These alkylsulfonates are linear, and have a carbon content ranging from C7 to C8 inclusive.

United States Patent 1191 Ali et 'a1.. 1 Oct. 9, 1973 1 DETERGENT COMPOSITION 3,393,154 7/1968 Treit1er.....' 252/554 x 51' n e to s ahid R. A; lliam R. Bryan; 3,496,224 2/1970 Ayers 252/554 X both of Pointe-a-Rierre, Trinidad Primary ExaminerLeon Dv Rosdol [73] Assignee: Texaco Trinidad, lnc., Assistant Examiner-Brucei-i. Hess Pointe-a-Pierre, Trinidad And Attorney-Thomas H. Whaley et al.

221 Filed: Aug. 5, 1971 [2,1] App]. No.1 169,505 [57] ABSTRACT [52] US. Cl. .l 252/554, 252/D1G. 14 Primary and secondary aikylsulfonates with carbon [51] Int. Cl Clld 1/14 numbers lower than those which afford optimum de- [58] Field of Search 252/554, 535, DIG. 14 tergency are used as hydrotropes in detergent formulations. These alkylsulfonates are linear, and have a [56] References Cited carbon content ranging from C-, to C inclusive.

' UNITED STATES PATENTS 3,011,977 12/1961 Raecke 252/554 X 5 Claims, NO Drawings DETERGENT COMPOSITION This invention relates to novel hydrotropes suitable for incorporation in detergent compositions.

Hydrotropes are salts which effect substantially greater solubility of slightly soluble substances than does water at the same temperature. This behavior is the opposite of the common salting out effect following the addition of many electrolytes to aqueous solutions of numerous solutes.

Typical of hydrotropes salts are the alkali or alkaline earth salts of the sulfonates of toluene, xylene. The most generally used hydrotrope in detergents is sodium xylenesulfonate because it is inexpensive and effective as a solvating agent. In the manufacture of heavy duty detergent powders they reduce the viscosity of the slurry before spray drying. In heavy duty liquid detergents they may act as solubilizers and coupling agents or even as cloud point depressants.

In accordance with the present invention it has been discovered that heptyl and octyl sulfonates can act as hydrotropes in detergent compositions when from 3 to 9 weight percent thereof are incorporated in such compositions.

The subject secondary alkyl sulfonates can be prepared by a sulfoxidation reaction disclosed and claimed in commonly assigned copending patent application Serial No. 40,740 filed on May 26, 1970.

In this reaction the C C n-paraffins alone or admixed are reacted with oxygen and sulfur dioxide under substantially anhydrous conditions in the presence of acetic anhydride or of a low molecular weight acyl oxide at temperature of about 25 c to about 55 oc under pressures of 0 to 100 psig.

The primary alkylsulfonates can be prepared by a bisulfite reaction involving reacting the l-olefin or 1- olefins with aqueous bisulfite in a mutual solvent under basic conditions at relatively low temperatures in the presence of an oxygen-containing initiator. This reaction is disclosed and claimed in commonly assigned copending application Serial No. 47,485 filed June 18, 1970.

For optimum results, reaction conditions, falling within the scope of the above mentioned applications, have been ascertained.

Surprisingly for the same set of conditions, the short chain olefins require longer reaction periods (l-20 hours) than the longer chain olefins (n8 hours). The analysis of the paraffin feedstocks used to prepare the secondary sulphonates is shown in Table II. The sulphoxidation reaction was carried out in a stirred tank reactor at atmospheric pressure. Reaction Conditions are summarised in Table III, and it should be noted that considerable difference exists between the reaction rates of the C and C paraffms. This is probably due to the large amount of impurities (mainly naphthenes) in the former sample (see Table II). Both the primary and secondary sulfonates have been analysed; the results are given in Table IV. Finally various surface active and detergent properties are summarised in Table V together with those of a linear alkylate sulfonate (Nacconol NF), included for comparison.

Viscosity measurements given below show that by incorporating 5 percent C and C alkylsulfonates, the viscosity of a 25 percent dodecylbenzene sulfonate solution (Nacconol NRSF) is reduced.

Viscosity Sample SSU at F. Nacconol NRSF (25%) 40 +O-Xylene sulfonate (5%) 33 +C-, Primary 34 +C Secondary 34 +C Secondary 33 The solubilizing properties were determined by (Table A) measuring the solubility of a given C -C primary alkylsulfonate sample, as well as on blends of this sample and the hydrotrope under investigation. In determining the solubility, sufficient water was added so that only little solids remained un dissolved. The carbon number distribution of the C C primary alkylsulfonate is shown in Table B. These compounds have optimum detergency.

TABLE A Sulfonate Sample Hydrotrope %Hydro- Solubility (Sulfonate) trope in of blend at blend 30 Mixture of C C and C C Primary sulfonate Nil Nil 4.3 g./100 ml O-Xylene 19 4.7 g./l00 ml C -Primary 22 12.8 g./l00 ml C -Primary 27 13.2 g./100 ml C -Secondary 26 17.2 g./l00 ml C -Secondary 23 16.8 g./100 ml TABLE B Carbon Number Distribution of C -C Primary Alkylsulfonate Gas Liquid Chromatography Identification C 3.5 C 5.0 i: 5.5 C 5.6 15 13.7 C 22.4 C,-, 21.6 C... 13.4 C 6.3 an C 0.5

TABLE I l-OLEFIN BISULPHITE REACTION CONDITIONS Reaction Temperature: 60C pH of Ammonium Sulphite Solution: 8.3 Initiator: t-butyl perbenzoate Run No. 520"" 517"" 522" 523 Charge Olefins, C No. C C C C moles 1.0 1.0 0.5 0.5 Sulphite, moles 1.0 1.0 0.5 0.5 volume, ml 620 620 310 310 iso-Propanol, ml 620 620 310 310 Reaction Time, Hr. 20 20 8 15 (a) In order to prepare large samples, it was necessary to do several runs and combine the products. The runs shown here are typical ones. (b) This run using C olefins is included for comparison to illustrate the difference in reactivity due to carbon chain lengths.

TABLE II ANALYSIS OF C-, AND C PARAFFINS USED IN SULPHOXIDATION C Sample TABLE III N-PARAFFIN/SULPI-IOXIDATION REACTION CONDITIONS A suitable range of detergent constituents employing the hydrotropes of this invention comprises.

Hydrotropes 20 to 30 weight percent, based on the total active matter content Detergent to 30 g. per 100 wt. solution (Na alkyl sulfonate) Foam stabilizer (fatty acid alkylolamide) O to 5 g.

per 100 wt. solution used (as required) Water balance.

More specific detergent formulations are the following (Na salts): (in parts by weight) A B C D Active Matter (eg LAS) 25 25 25 25 C Primary alkylsulphonate 5 C Primary 5 C, Secondary 5 C Secondary 5 A suitable method for determining whether the described hydrotropes are biodegradable is not available. The Soap and Detergent Association method of analysis is insensitive to C,C,. and other short chain alkylsul- A fonate. However, as the alkyl chains are linear, the compounds are probably biodegradable.

What is claimed is:

1. A detergent composition consisting of about 3 to 9 weight percent of a C or C linear alkylsulfonate as a hydrotrope, from 15 to 30 weight percent of linear alkylsulfonate detergent having 11 to 19 carbon atoms in the alkyl moiety, up to 5 wt. percent of a fatty acid alkylolamide foam stabilizer and the balance water.

2. A composition according to claim 1 containing about 5 parts by weight of a C primary alkylsulfonate and about 25 parts by weight of a linear alkylsulfonate having a carbon content in the C C range.

3. A composition according to claim 1, containing about 5 parts by weight of a C secondary alkylsulfonate and about 25 parts by weight of a linear alkylsulfonate having a carbon content in the C, C range.

4. A composition according to claim 1 containing about 5 parts by weight of a C secondary alkylsulfonate and about 25 parts by weight of a linear alkylsulfonate having a carbon content in the C -C range.

5. A composition according to claim 1 containing about 5 parts by weight of a C primary alkylsulfonate and about 25 parts by weight of a linear alkylsulfonate having a carbon content in the C C, range. 

2. A composition according to claim 1 containing about 5 parts by weight of a C7 primary alkylsulfonate and about 25 parts by weight of a linear alkylsulfonate having a carbon content in the C11-C19 range.
 3. A composition according to claim 1, containing about 5 parts by weight of a C7 secondary alkylsulfonate and about 25 parts by weight of a linear alkylsulfonate having a carbon content in the C11-C19 range.
 4. A composition according to claim 1 containing about 5 parts by weight of a C8 secondary alkylsulfonate and about 25 parts by weight of a linear alkylsulfonate having a carbon content in the C11-C19 range.
 5. A composition according to claim 1 containing about 5 parts by weight of a C8 primary alkylsulfonate and about 25 parts by weight of a linear alkylsulfonate having a carbon content in the C11-C19 range. 